Abstract

Doc number: 128

Abstract

Background: Serotonin (5-HT) is a well-known modulator of eating behavior. However, the molecular mechanisms linking its action to body weight balance have been only partially elucidated. Since platelets are a suitable peripheral model to study 5-HT transport, metabolism and release, we herein evaluated the expression of the platelet 5-HT re-uptake system (SERT) by [3 H]-paroxetine binding assay. A cohort of 114 unrelated individuals (34 males, 80 females; age, mean ± SD: 38.57 ± 12.47 years) without major psychiatric disorders, was recruited following a naturalistic design regarding age or gender and classified accordingly to their body mass index (BMI). Subjects were divided into 5 groups: normal-weight (NW), overweight (OW) and grade I-III obese (OB) individuals. For gender analyses, data were transformed into [3 H]-paroxetine density (Bmax )/BMI ratios to overcome both the disparity of women vs. men number and anthropometric differences between sexes.

Results: [3 H]-paroxetine Bmax (SERT density, fmol/mg proteins) was reduced in platelet membranes of grade II (p < 0.01) and III (p < 0.001) obese subjects vs. controls and in overweight subjects (p < 0.05) vs. grade III obese individuals. Considering all patients together, a strong negative correlation between Bmax and BMI (r = -0.449; P < 0.0001) was demonstrated. Conversely, [3 H]-paroxetine KD (dissociation constant, nM) did not differ among groups. No gender-related variation concerning Bmax /BMI ratios was observed in this cohort of subjects.

Conclusions: The down-regulation of SERT in platelet membranes of severe human obesity (BMI > 35 Kg/m2 ) confirms the involvement of 5-HT system in body weight gain. Moreover, this findings may help to elucidate those monoamine-endocrine networks acting on fat storage, adipocyte signaling and energy balance. Targeting 5-HT/5-HT-related markers will possibly uncover the existence of human obesity subtypes.

Details

Title
The expression of platelet serotonin transporter (SERT) in human obesity
Author
Giannaccini, Gino; Betti, Laura; Palego, Lionella; Marsili, Alessandro; Santini, Ferruccio; Pelosini, Caterina; Fabbrini, Laura; Schmid, Lara; Giusti, Laura; Maffei, Margherita; Lanza, Mario; Cristofaro, Mario; Baroni, Stefano; Mauri, Mauro; Vitti, Paolo; Fierabracci, Paola; Lucacchini, Antonio
Pages
128
Publication year
2013
Publication date
2013
Publisher
BioMed Central
e-ISSN
14712202
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
1454508582
Copyright
© 2013 Giannaccini et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.